Harlow and Zimmerman's Monkey Experiments

• Harlow & Zimmerman investigated how attachment to a mother was not based on feeding but instead, attachment is formed through being comforted
• Procedure:

  • Two fake wire mother monkeys were created. Each had a different head and body type. One was covered in cloth and one was bare wire with no padding
  • Eight monkeys were split into two groups and studied over 165 days
  • One group had milk dispensed via the cloth mother and the other via the wire mother
  • Data was collected and observatins were made on the monkeys behaviour
• Findings:

  • All eight monkeys spent the majority of time with the cloth mother
  • Monkeys whose milk was delivered via the wire mother only spent their time feeding, then returned to the cloth mother
  • When scared all monkeys held onto the cloth mother
  • This suggests that contact and comfort are how attachment is formed, rather than through feeding.
• Harlow & Zimmerman also observed the monkeys into adulthood to investigate maternal deprivation. Monkeys raised with the wire mother were the most dysfunctional:

  • More aggressive
  • Less sociable
  • Bred less/unskilled at mating
  • Attacked their offspring
• Harlow & Zimmerman also discovered a critical period for dysfunctional behaviour. The monkeys who spent time socialising with other monkeys before the age of three months showed that some of the abnormal behaviour could be reversed.
• A strength of this research is that it provides strong evidence that attachment in primates revolves around a deep emotional need, not just food. This can be used to challenge the learning theory and would explain why humans are closely attached to an adult who does not feed them.